A power converter includes a switch controller generating a pulse signal controlling a switch to emulate peak current mode control. The switch controller generates a control voltage from a representation of an output voltage of the power converter and a reference voltage. Based on the control voltage and a representation of an input voltage of the power converter, the switch controller determines a peak current in that switching cycle. If the peak current detected exceeds a maximum peak current, an on-time of the pulse signal in the next switching cycle is decreased. The power converter also provides short circuit or overload protection by increasing an off-time of the pulse signal until the off-time exceeds a transformer reset time of a transformer. If the switch period increased to prevent short circuit or overload exceeds a limit, the pulse signal is shut off immediately.